BiSI薄膜紫外光电探测器的研究

Study on BiSI Thin Films for Ultraviolet Photodetectors

三元硫卤化物BiSI具有光电导率高、光吸收系数高(】105 cm−1)和带隙宽度(1.57 eV)合适等优点,在光电领域得到了广泛的应用。目前BiSI晶体和薄膜的常见制备方法中存在工序复杂、合成温度高、反应时间长和易引入BiOI杂相的缺点,在光电探测器方面的应用鲜有报道。本工作提出一种温和简便的方法——先采用气相法沉积BiI3薄膜,再经H2S气氛处理获得BiSI纳米线薄膜。将该薄膜组装成器件应用于光电探测,发现器件在300~800 nm的波段内均具有响应,尤其在紫外光(370 nm)照射下,器件的响应度和探测率可达到最高,分别为6.30 A/W和7.78 ×1011 Jones。本工作不仅证明了该方法的可行性,也为BiSI薄膜在紫外光电探测器领域的应用提供了参考。

Ternary sulfide halide BiSI has been widely used in the photoelectric field due to its high photo-conductivity, high optical absorption coefficient (>105 cm−1) and suitable band gap width (1.57 eV). At present, common preparation methods of BiSI crystals and thin films have disadvantages such as complex process, high synthesis temperature, long reaction time and easy introduction of BiOI heterophase. There are few reports on applications in photodetectors. In this work, a mild and simple method was proposed, BiI3 thin films were deposited by gas phase method, and then BiSI nanowire thin films were obtained by H2S atmosphere treatment. The photodetectors based on BiSI film showed photoresponse in the range of 300~800 nm. Especially, in the condition of ultraviolet light (370 nm), it displayed high performance, including high responsivity up to 6.30 A/W, and high detectivity of 7.78 ×1011 Jones. This work not only proves the feasibility of the method, but also provides a reference for the application of BiSI thin films in the field of ultraviolet photoelectric detectors.